Two brothers, one a popular race car driver that all the women love and the other a brilliant mechanic who makes the winning possible, become enemies when one messes with the other's girlfriend.

Stock car driver Marty gains the admiration of the crowd, while his brother Del, a mechanic, smoulders on the side lines. A third brother, Steve, a revenue agent, tries in vain to keep peace in the family. Intending to win fame for himself, Del opens his own garage, building souped-up "tankers" for moonshiners on the side. His girl friend Sue is upset but cannot stop him. Del makes a proposition to the owner of a car often beaten by Marty and is allowed to drive against his brother. Flushed with victory in a race that almost costs Marty his life, Del tries to break away from the moonshine ring, but both he and Marty are abducted by the gang. As Steve and a squad of revenue agents close in, Marty and Del escape, with the moonshiners in hot pursuit. Rounding a curve, the moonshiners' car goes out of control, and they plunge to their deaths. Marty and Del then help Steve round up the remaining criminals. Secure in the knowledge that he is a good driver as well as mechanic, Del apologizes to Marty, and the two combine to become the most sensational team in stock car history.